1. Field of the Invention
The present invention relates to an image reading apparatus, an image recording medium and an image forming apparatus. Specifically, the present invention relates to an image reading apparatus, which reads silver images recorded on a color photosensitive material on the basis of light reflected by the color photosensitive material and light transmitted through the color photosensitive material; an image recording medium, on which image data or the like read by the image reading apparatus is recorded; and an image forming apparatus, which regenerates the image data recorded on the image recording medium so as to form images.
2. Description of the Related Art
A photosensitive material using silver halide has been developed more and more in recent years, and at present, high-quality color images can be easily obtained. For example, in a method generally called color photography, the photography is performed by using a color negative film, and image information recorded on the color negative film, which has been developed, is optically printed onto a color photographic printing paper so as to obtain a color print. In recent years, this process has been developed to a high degree, and large-scale centers which produce a large number of color prints with high-efficiency, i.e., large laboratories, or small and simple printer processors located at stores, i.e., mini-laboratories have been spread. As a result, everyone can easily enjoy color photography.
A principle of color photography which is popular at present employs color reproduction due to a subtractive color process. In a general color negative, photosensitive layers using silver halide emulsions, which are photosensitive elements in which photosensitivity is imparted to blue, green and red areas, are provided on a transmissive support, and so-called color couplers which form yellow, magenta and cyan dyes, each of which is a hue which is to become a complementary color, are combined and contained in the photosensitive layers. The color negative film, which has been exposed image-wise by photography, is developed in color developer containing an aromatic primary amine developing agent. At this time, the exposed silver halide particles are developed, i.e., reduced by the developing agent so as to produce metallic silver, and simultaneously produced oxidants of the developing agent are coupled with the above-mentioned color couplers so as to form each dye. The metallic silver (developed silver) generated by the development and unreacted silver halide are respectively removed by bleaching and fixing processes so as to obtain color images. A color photographic printing paper, which is a color photosensitive material, in which photosensitive layers having a combination of photosensitive wavelength areas and color hues which are similar to those of the film are applied onto a reflective support, is optically exposed through the developed color negative film; and the color photographic printing paper is subjected to the same color developing, bleaching and fixing processes. As a result, color prints consisting of color images in which original scenes are reproduced can be obtained.
These systems are being widely spread at present. However, it is being more and more strongly required that the simplicity of the systems be improved. For example, in Japanese Patent Application Laid-Open (JP-A) No. 6-295035 and U.S. Pat. No. 5,519,510, an image forming method is described, in which, without forming dye images, image information representing image-exposure for each of blue, red and green portions is extracted from silver halide color photographic elements, i.e., silver images. In this method, photosensitive material can be designed without using coloring material, and even if coloring material is used, images can be read without coloring. Further, in this method, one image is read a number of times at predetermined intervals, and a satisfactory image in a wide dynamic range is obtained.
In a case in which images are read from a monochromatically developed color photographic film in this manner, reading conditions, which are completely different from those in a general case in which images are read from a color-developed color photographic film or from a monochromatically developed monochromatic photographic film, are required. However, in conventional processing systems, the monochromatically developed color photographic film could not be distinguished from the other films, and thus, such problem that reading is not suitably performed was caused.
Moreover, a color photographic film is originally used to form transmitted images. While a color paper efficiently reflects light by a baryta layer thereof, a color photographic film does not have a function for efficiently reflecting incident light, and thus, a large quantity of light is lost at the time of image reading. Therefore, there was such problem that, if the quantity of light is not large or a lot of time is not spent when the reading is performed, it is difficult for photoelectric conversion elements to obtain sufficient light and output signals with a high SN-ratio.
Further, when images are read from a support side (base side), an anti-halation layer consisting of silver colloid damps the light. Therefore, there was such problem that, if an even larger quantity of light is not irradiated or if a longer time is not taken for reading, the signals with a high SN-ratio cannot be obtained.